Abstract：Microwave irradiation activation has some unique advantages in improving the activity of fly ash, which is a kind of active excitation technology with high speed, low energy consumption and low carbon. In this paper, the effect of microwave irradiation power (500 W, 800 W, 1 000 W) on the activity of fly ash was studied, and the microstructure of fly ash was characterized by X-ray diffraction (XRD) and scanning electron microanalysis (SEM-BSE), and the influence mechanism of active fly ash on cement hydration was studied. The results showed that microwave irradiation can improve the potential activity of fly ash. The optimum microwave irradiation power was 1 000 W, and the activity index of 28 day was 80.89%. After microwave irradiation, the fly ash particles were partially or completely broken, and the amorphous phase content increased by 17.74%. The hydration heat of fly ash-cement irradiated by microwave can reach the final setting 0.56 h earlier, and the area of unhydrated cement at 7 days was 15.8% lower than that of original fly ash-cement slurry, which showed that the hydration process of cement was obviously accelerated
2024, Vol. 0 
